HKE and CLP both provide this concept of "Maximum Demand Tariff" or MDT which has the potential to lower energy cost for high energy consumer. In the investigation summarized below, I focused on HKE because they provide a simpler MDT scheme (not necessary cheaper or better).

Hong Kong Electric provides an excellent explanation on how a customer will be billed if they opted for the "Maximum Demand Tariff"

As their example showed, opting for the Maximum Demand Tariff may not be beneficial for all customer. As HKE has pointed out on their website:

Maximum Demand Tariff consists of two parts, i.e. demand charge and energy charge. The demand charge is based on the maximum demand in kVA, while the energy charge depends on the energy consumption in Unit (kWh) of the month. Tariff charges are subject to a minimum of 100 kVA of the chargeable demand.
Maximum Demand Tariff is only beneficial to electrical installations with a high load factor. This applies to accounts of considerably high electricity consumption over a long period of time with a steady load. If these conditions are not satisfied, it is possible that the electricity charge could be higher under Maximum Demand Tariff than Commercial, Industrial & Miscellaneous Tariff.

Looking into the concept of Maximum Demand and the calculations, it will be most beneficial to customers with a more constant load over time and a high power factor. This is because the maximum demand charge, at least in the HKE's case, is calculated using the peak average apparent power in a 30 minutes period within the billing period (1 month).

The observation where a customer with a more constant load will benefit by using the Maximum Demand Tariff billing method is pretty straightforward. Since the peak usage is close to the average energy usage, the demand charge will be small relative to the energy charge.

Power factor plays a role in the calculation is due to the fact that Demand Charge in the "Maximum Demand Tariff" is measured in VA (Apparent Power) vs. W (Real Power) as in Energy Charge.

If we also make the assumption which typical loading factor is around 0.1 - 0.3 range, from the above plot we can see that we can reduce the energy consumption bill under the MDT scheme by:

Improving the load factor: spreading the load across time especially during peak energy consumption

Improving the power factor of the loading during the maximum demand period.

For the next step, it is probably worth quantifying the cost of improving the power factor of the entire loading of the energy consumer vs shifting loads from peak time to other times. Combined with the information in this post, we will be able to calculate the ROI on projects aimed at improving either the load factor and/or power factor.